Database Environment & ANSI SPARC Flashcards
What is Metadata in the context of a database?
it is data about the database itself
What is a System Catalog?
A repository in the database system that stores metadata
What are the other terms of a System Catalog
Data Dictionary or Metadata
What does a System catalog do?
Describes the structure, organization, constraints, and relationships of a DB system. It also ensures the DBMS has the needed information
Enumerate the contents of a System Catalog
HINT: TIVURS
- Tables and Columns
- Indexes
- Views
- Users and Roles
- Relationships
- Statistics
This refers to hiding the complexities of data storage and management from end users
Data Abstraction
What are the 3 levels of Data Abstraction
Physical, Conceptual, External
This level of abstraction describes how data is stored in physical storage devices
Physical Level
This level of abstraction provides a unified view of the database
Conceptual Level
This level represents views with relevant data tailored for specific users and applications
External Level
What are the Components of a Database Environment
HINT: HSDPP
- Hardware
- Software
- Data
- Procedures
- People
Servers, storage devices, and network infrastructure belong to which DB environment component?
Hardware
DBMS, OS, and applications belong to which DB environment component?
Software
Backup and recovery, Security Policies, and maintenance belong to which DB environment component?
Procedures
This is the heart of the DB environment, acting as the bridge connecting, hardware, software, and users
Data
What are the 3 types of Data?
User Data, Metadata, Indexes
This data represents the actual records stored in tables
User Data
This data represents info about the database structure
Metadata
This data represents structures for optimizing query performance
Indexes
What are Procedures in the DB environment
They define rules, policies, and guidelines for using and managing the DB system
These types of Users are involved in the design, development, and maintenance of the database
Technical Users
These types of Users access the database only to perform their job functions and do not need to know how the database works
Non-Technical Users
What is the ANSI-SPARC architecture?
A conceptual framework standardizing how databases are organized and interacted with.
What does ANSI-SPARC stand for?
American National Standards Institute, Standards Planning And Requirements Committee
What are the three levels of abstraction in ANSI SPARC?
- Physical Level / Internal View
- Conceptual Level / View
- External Level / View
This view describes how data is stored on hardware
Physical View
This view defines the logical schema of the database
Conceptual View
This view Represents user-specific views of data
External View
This refers to a logical and user-defined abstraction of data
View
This refers to the form, structure, or model in which data is organized or stored
Representations
How do Representations differ from Views?
Representations are a broader concept and encompass all ways data is modeled, stored, or presented, regardless of user interaction
What are the two types of representations, explain what they are.
- Physical Representation: Physical storage of data
- Logical Representation: How the database logically structures data
These are dedicated machines where the DBMS and database reside
Servers
This connects clients to the database server
Network Infrastructure
It is the core software managing data storage, retrieval, and manipulation
DBMS
Provides an interface between hardware and software
Operating System
